Incidents on battery installations: identification, reaction and securing*
Battery systems, even at low voltage (48–51.2 V), can present risk situations when they are misused, damaged, or subjected to abnormal conditions.
Reactivity and mastery of good practices are essential to prevent injuries, material damage, and fires.
This article presents the main types of possible incidents and the immediate responses required.
1. Short circuit or electrical arc
Symptoms: spark, crackling, black mark on terminals, sudden release of heat or light.
Actions to take:
Immediately cut the power supply or operate the main switch.
Remove any conductive source (metal tool, fallen cable, poorly fixed part).
Once the area is secured, visually inspect the cables, connectors, and terminals to identify points of melting, blackening, or deformation.
Systematically replace any cable, connector, or terminal showing signs of heating, arcing, or burning.
Before returning to service, check the insulation and tightening of connections.
A short circuit, even brief, can weaken a cable or cell; never reuse a suspect element.
2. Abnormal heating
Symptoms: battery hot to the touch, smell of heat, slight degassing noise, accelerated ventilation.
Immediate response:
Stop use immediately and cut the power supply.
Ventilate naturally the area to dissipate heat (do not use compressed air).
Check the temperature of modules, connectors, and cables.
Identify the root cause:
discharge current too high,
insufficient thermal dissipation,
excessive contact resistance (insufficient tightening or oxidation).
After complete cooling, measure the cell voltage and check the BMS logs before any restart.
A localized temperature rise is an early warning signal of failure.
3. Smell, smoke, or electrolyte leak
Symptoms: acrid or sweet smell, white smoke, liquid or powdery seepage around the pack.
Conduct to follow:
Immediately isolate the area and deny access to anyone not equipped.
Wear appropriate PPE: insulating gloves, visor, mask, and covering clothing.
If leak or visible deposit, absorb with an appropriate product (mineral binder, neutral industrial absorbent) and place residues in a hermetic container for specialised treatment.
Never spray or chemically neutralise without manufacturer's instructions: some reactions are violent with water.
Contact the approved treatment channel (or the system supplier) for evacuation and disposal according to local regulations (e.g. Hazardous waste – DIB/DIS code).
Any pack that has shown a leak or emission must be reported, isolated, and permanently removed from service.
4. Start or outbreak of fire
Precursor signs: crackling, dense smoke, rapid temperature rise, overpressure vent noise.
Immediate actions:
Apply local fire instructions and alert emergency services.
If personnel safety is guaranteed:
Use water in a diffuse jet or mist to cool neighbouring batteries and limit the spread.
Use a CO₂ or ABC extinguisher on peripheral equipment (cables, boxes, supports).
Do not attempt to open or move a burning pack.
After extinction, isolate the area for several hours: a thermal runaway is possible.
Never reuse a pack involved, even partially, in a fire.
Only the manufacturer or an approved body can assess the residual safety of the system.
5. Conclusion
In the face of any battery incident, the safety of people takes precedence over the preservation of equipment.
The right reflexes are: cut, isolate, protect, alert, analyse.
A complete inspection after each event is essential to avoid recurrence and ensure the long-term reliability of the installation.
A well-designed and well-maintained battery system significantly limits risks — but it is the rigour of interventions and checks that ensures true safety.
*: The technical information presented in this article is provided for guidance only. It does not replace the official manuals of the manufacturers. Before any installation, handling, or use, please consult the product documentation and follow the safety instructions. The site Torque.works cannot be held responsible for inappropriate use or incorrect interpretation of the information provided.